Primary tumours of the optic nerve and the optic nerve sheath

Introduction: Glioma and meningioma, the 2 most common primary tumours of the optic nerve and optic nerve sheath are usually benign, slow-growing tumours.

The aim of the paper is to provide an overview of clinical, histo-logical and radiological features of the most common primary tumours of the optic nerve and optic nerve sheath, as well as to discuss available treatment options.

Materials and methods: A literature review was performed based on articles discussing optic nerve glioma and meningioma of the optic nerve sheath.

Results: Glioma is the most common primary tumour of the optic nerve. In 90% of the patients, the onset is within the first 2 decades of life. Meningioma is the most common primary tumour of the optic nerve sheath. In 95% of the sufferers, the onset is in adulthood. Although rare in the general population, primary tumours of the optic nerve and its sheath are seen more often in patients with neurofibromatosis (NF). Glioma more

often affect patients with NF1, whereas meningiomas more often affect those with NF2. Unlike in children, optic nerve glioma in adults can be malignant. On the other hand, optic nerve sheath meningioma tends to be more malignant in children rather than in adults. The symptoms of optic nerve glioma and optic nerve sheath meningioma can be similar, including vision impairment and proptosis. The diagnosis is based on orbital imaging with magnetic resonance image (MRI) or computed tomography (CT). The management most often involves clinical observation. Surgery, radiation therapy or chemotherapy are only used in selected cases with the risk of optic chiasm or fellow optic nerve involvement.

Conclusions: Primary tumours of the optic nerve and optic nerve sheath are rare. Consolidated knowledge and improved understanding can aide early diagnosis and proper management of such cases.